Week 1 CNS Objectives 4 Functions of Dendrites for exiting Neurons

Question 1

T/F dendrites generally cannot transmit action potentials

Answer 1

T

Question 2

What kind of conduction do dendrites use?

Answer 2

electrotonic conduction

Question 3

Two traits about dendrites

Answer 3

they are long and possess thin membranes

Question 4

Dendritic membranes are partially permeable to

Answer 4

potassium and chlorine

Question 5

What kind of potential does a dendrite carry and where does it go exactly?

Answer 5

Localized potentials are largely lost due to leakage

This process of losing potential is called decremental conduction

Question 6

Decremental conduction: definition

Answer 6

conduction caused by ion movement which doesn’t generate an action potential

signal becomes weaker the further it goes; this is the opposite of action potentials which maintain their strength as they move along the axon

Question 7

Causes of decremental conduction

Answer 7

few voltage gated sodium channels in dendritic membranes

thresholds too high for action potentials to occur

Question 8

Excitatory/inhibitory state of the dendrite is defined as

Answer 8

summated degree of excitatory drive to the neuron

excitatory state occurs when there is a higher degree of excitation compared to inhibition

inhibitory occurs where there is a higher degree of inhibition compared to excitation

ratio of excitation/inhibition defines which direction it goes

Question 9

Synapse Delay

Answer 9

Refers to the amount of time it takes for a signal to synapse between a presynaptic neuron and a postsynaptic neuron

Question 10

Time Considered in a Synapse Delay

Answer 10

1. Time it takes for the presynaptic neuron to release the neurotransmitter
2. Time it takes for the neurotransmitter to diffuse across the synaptic cleft
3. How the neurotransmitter acts on the synaptic membrane
4. How long it takes the receptor to cause membrane permeability to occur
5. Time is takes for the inward diffusion of sodium ions